The present invention relates to a manual air pump for two wheel tires. More particularly it relates to a manual air pump which has a head and two oppositely located connecting elements for connecting a pump chamber with a respective one of the wheel tires.
Manual air pumps of the above mentioned general type are known in the art. Such pumps are used for pumping wheels of bicycles as well as wheels of motorized bicycles, for which purpose two connecting elements for respective valves are provided. Thereby different valves can be connected with the same pump and the connecting elements can be fitted directly on the valve. It is well known during the utilization of a manual pump to bring the valve on the wheel in upper position so that it extends upwardly and the used connecting element of the pump assumes an upwardly directed position.
The French document FR-PS 544,366 discloses a pump head for power vehicle wheels with two mating elements for valves of different sizes. The conversion of the air stream from one to the other connecting element is performed by rotating of a valve plug. The German document GE-PS 380,975 discloses a manual pump for pumping vehicle tires. The different connecting elements are received in a transverse pipe in the head which admits the pumped air through an opening in the tubular wall. The transverse pipe is formed as a cylinder with a piston which guides the pumped air to one or another connecting element depending on the position of the piston at one or another side of the supply opening. The displacement of the piston is performed by screwing-in of a hose in one of the connecting elements. Thereby in this known manual air pump only one connecting element for direct fitting on a valve is suitable. Finally, the French document FR-PS 983,471 discloses a connecting device for pumping tires with a cylinder which on each end is provided with a connecting element connected with a supply passage and which also has a piston in which to supply the air to one or another connecting element depending on its position relative to the supply passage. The displacement of the piston is performed pneumatically. The known arrangements are suitable for automobile tires.